This invention relates to what is known as a chipping cutter head, sometimes referred to as chipping canter. A cutter head of this description is usable to remove, in the form of chips, material cut from an article such as a log to produce a cant from the log. The usual cutter head includes a body with shaft extensions extending from opposite ends of the body. The cutter head is rotatable about the axis of these extensions. Cutting elements or knives are distributed about the circumference of the cutter head body, and these cut chips in a planing type action from the wood material being processed.
A conventional type of chipping cutter head known in the past has included what might be described as cavities distributed about the circumference of the body in the cutter head. Knife bodies are detachably mounted within these cavities, and these knife bodies are provided with sharp knife edges that move in circumferential sweeps with rotation of the cutter head to produce the cutting action. The knife body must periodically be removed for sharpening purposes and after sharpening it is returned to its respective cavity. For the knife bodies to be properly mounted with their cutting edges positioned to produce the type of cutting action desired, babbitting or shimming of the body is performed, which is effective to adjust the position of the body and the cutting edge which the body includes. With a great many knife bodies ordinarily making up a cutter head, the procedure outlined obviously is a time consuming one, requiring skill and experience.
More recently there has been developed a cutter head which has included replaceable, doubled-edged knife elements or knives suitably distributed about the periphery of a cutter head body. When one edge of the knife element is dull, it is turned on itself to expose its other cutting edge. When both of its cutting edges are dulled, the knife element is replaced by a new knife element. Clamp structure is provided which releasably holds a knife element in a proper position. A cutter head with knives of this description is disclosed in our prior issued U.S. Pat. No. 5,146,963 entitled "CHIPPING DEVICE" issuing Sep. 15, 1992.
While a chipping cutter head as set forth in the aforementioned patent has been demonstrated to have substantial advantages over cutter heads with knife bodies that are removed and resharpened to be returned on dulling, in certain applications it has been found desirable to include additional structure in the cutter head functioning accurately to position a knife in the cutter head, and firmly to establish its position even after being subjected to frequent and substantial jarring and shocks as is common with a chipping cutter head. This invention addresses the problem of mounting a knife or knife element so that it is securely held in an established position on the cutter head.
The invention further addresses the problem of providing a wear surface for each of respective knives in a cutter head, where the wear surface is part of a replaceable mounting insert, which is easily replaced when mandated by wear occurring in an installed insert, or should a differently shaped wear surface be desired for the purpose of producing a different size and type of chip. The mounting insert, while detachable and replaceable, is incorporated in the support structure for the knife in such manner that the insert is positively mechanically held from displacement during use of the cutter head.
Also a feature of the invention is the provision of a chipping cutter head which incorporates in a novel fashion a removable splitter element which functions to split chips produced with the knife of a cutter head. Further explaining, with certain species of wood, and under certain temperature conditions, chips produced by a cutter head may have a greater size than the optimum size desired. A splitter element incorporated with the cutter head splits chips cut by the cutter head to reduce their size. While splitting may be desirable with a pine species, under certain temperature conditions with other species, or with frozen wood, splitting may not be necessary. With the construction contemplated by the invention, a splitter element is easily incorporated into the cutter head for association with each knife in the cutter head. The cutter head may be run with or without the splitter elements, and the splitter elements are easily changed or removed without making a change in knife setting.